Cam system,especially for multi-feed circular knitting machines



* D. ROTHE 3,520,153

CAM SYSTEM, ESPECIALLY FOR MULTI-FEED CIRCULAR KNITTING MACHINES 2 Sheets-Sheet Filed May 2, 1968 INVENTOR DIETER ROTHE July 14, 1970 D. ROTHE 3,520,153

CAM SYSTEM, ESPECIALLY FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed May 2. 1968 2 Sheets-Sheet 2 INVENTOR DIETER ROTHE United States Patent 3,520,153 CAM SYSTEM, ESPECIALLY FOR MULTI-FEED CIRCULAR KNITTING MACHINES Dieter Rothe, Mittweida, Saxonia, Germany, assignor t0 VEB Strickmaschinenbau Karl-Marx-Stadt, Karl-Marx- Stadt, Germany Filed May 2, 1968, Ser. No. 726,172 Int. Cl. D04b 15/32 US. CI. 6657 3 Claims ABSTRACT OF THE DISCLOSURE A cam system for use in knitting machines with a needle bed, comprising a tuck cam member and a clearing cam member rotatable with respect to each other and respectively mounted on a hollow shaft and a solid shaft received in the hollow shaft, the two cam members being provided with partially or temporarily cooperating abutment means operable to permit independent rotation of the cam members in opposite directions with respect to each other while effecting rotation of one cam member by the other when rotating towards each other.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a cam system for knitting machines, especially multi-feed circular knitting machines. More specifically, the invention relates to cam systems comprising a tuck cam member and a clearing cam member, both rotatable about an axis perpendicular to the needle bed of the knitting machine. Both cam members or cam parts are rotatably journalled on a cam carrier, of the knitting machine, one of the cam members being carried by a hollow shaft whereas the other cam member is carried by a shaft received within the hollow shaft.

Prior art Such a cam system is, for instance, known from German Pat. No. 1,099,121 showing a manual knitting machine. This cam system is journalled directly below the clearing track of the needle butts, and the two individual cam members or parts of the cam system are continuously interconnected for rotation. In order to produce a clearing track the entire cam system must be rotated downwardly so that the needle butts running in the knock-over path art lifted first by the tuck cam member and subsequently by the clearing cam member. If the needles are to remain in the knock-over position, the entire cam system is rotated upwardly by a distance exceeding the width of the needle butts so that the needle butts may pass thereunder. For producing a tuck track, the clearing cam member is adapted to be retracted towards the front from the plane of the needle butts while the tuck cam member remains in its operative or working position. To this end, the shaft carrying the clearing cam member is displaceably arranged within the hollow shaft carrying the tuck cam member.

This arrangement requires not only to provide stop and arresting means for the cam system which limit and fix the rotating movements of the same, but also to provide additional means which hold the shaft of the clearing cam member in its two axial positions. Therefore, this known cam system is relatively complicated and very often causes disturbances and failures in the operation of the knitting machines.

Moreover, due to the fact that the cam system is rotatable and the tuck cam member is adjustable independently thereof perpendicularly to the needle bed, adjusting and setting errors may easily occur. Furthermore, this known cam system cannot be employed with circular "ice knitting machines where the needles are inserted without gaps therebetween since the needle butts permit neither a rotating movement of the tuck cam member, of the cam system nor a displacing movement of the clearing cam member of the system in its operative or working position.

BRIEF SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a cam system for knitting machines, especially multi-speed circular knitting machines of the general type referred to above, which will overcome the above mentioned drawbacks and disadvantages.

It is another object of the present invention to provide a rotatable cam system as set forth above which is simple in structure and which is more reliable in operation than heretofore known cam systems in knitting machines while facilitating the operation and actuation thereof.

It is still another object of the present invention to provide a rotatable cam system which may be employed without difficulty in multi-feed circular knitting machines.

It is still a further object of the present invention to construct the cam in such a way that the non-knitting track, the clearing track and the tuck track of the needle butts are achieved by mere rotating movements. With heretofore known cam systems this is impossible especially in multi-feed circular knitting machines, since this would require that for purposes of establishing the tuck track the clearing cam member is tilted or rotated into an ineffective position. There is simply no space in the cam systems of multi-feed circular knitting machines since immediately in front of the cam system a cam member is located which forms a channel for the butts therewith and since the stitch cam follows immediately the cam system.

The above objects have been achieved according to the invention in a cam system by a needle lifter comprising two individual cam members, which are journalled and individually rotatable below the nonknitting track of the needle butts and which point in the running direction of the needles in their operative position, while in the operative position of the cam system the free end of the cam system overlaps and abuts the lower portion of the working edge of the clearing cam part so that following the tuck cam part the clearing cam part is movable from the inoperative to the operative position, and conversely, following the clearing cam part the tuck cam part is rotatable from the operative position into the inoperative position.

A very advantageous arrangement is obtained if the clearing cam part is connected to the hollow shaft, and the tuck cam part is connected to the shaft which is received in said hollow shaft.

BRIEF DESCRIPTION OF THE DRAWINGS With these and other objects in mind the invention is illustrated, by way of example, in the accompanying drawings, in which:

FIGS. 1, 2 and 3 illustrate various positions of the cam members of the cam system according to the present invention which is incorporated in the cylindrical carn system of a circular knitting machine; and

FIG. 4 illustrates a cross-section through the cam system and its supporting and actuating means.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing in detail and to FIGS. 1-3 thereof in particular, the arrangement shown therein comprises a cam system generally designated with the reference numeral S including two cam members of a clearing cam H, a stitch cam, a non-knitting member 2 and a member 3 H, a needle sinker 1, the circular run- 3 ning portion 2 and 3 which together with the clearing cam H forms the butt guiding channel 4 when the needle clearing cam H occupies its operating position.

Clearing cam H comprises a tuck cam part 5 and a clearing cam part 6. The latter is connected to the inner end of a hollow shaft 7, whereas the tuck cam part or member 5 is connected to the inner end of a shaft 8 received in the hollow shaft 7.

As will be seen from FIG. 4, hollow shaft 7 is received in a bore 9 of a carrier 10, which bore 9 perpendicularly to the broad side of a needle bed (not shown). The twopart clearing cam H is journalled below the non-knitting track of the needle butts, and more particularly in such a way that it can be rotated in its entirety into a recess 11 of the non-knitting member 2, as shown in FIG. 3. The needle butts can, in this position, run unimpededly over the upper edge of the member 2. From this position, the entire clearing cam H is rotatable upwardly for purposes of establishing the clearing track of the needle butts into the operating position shown in FIG. 1. If the tucking position is to be established, the clearing cam part 6 remains in the recess 11 of the non-knitting member 2 and only the tuck cam part 5 is rotated upwardly into the operating position, as shown in FIG. 2.

With reference to FIG. 4, the tuck cam part 5 is received in a recess 12 on the inside of the clearing cam member 6. The free end of cam part 5 covers and overlaps the lower portion of the working edge of the clearing cam member 6 (see FIGS. 1 and 4). At this portion, the working edge of the tuck cam part 5 forms a corner which covers the working edge of the clearing cam member or part 6 so that the needle butts remain for a short distance in a horizontal intermediate path following the lifting into the tucking track and prior to the lifting into the clearing track. Since a portion of tuck cam part 5 covers the clearing cam member 6, a partial dependency of movement between the two individual cam members is achieved. Thus, it is not possible to move the clearing cam member 6; alone into the operating position in the upward direction and it is also not possible to move tuck cam member 5 independently and alone into the recess 11 of the nonknitting member 2.

Two adjusting arms 13 and 14 are each connected to the outer end of the hollow shaft 7 and shaft 8. An arresting pin 15 with a knob 16 is attached tothe free end of each of these adjusting arms 13 and 14. Recesses 17 for these arresting pins 15 corresponding to the positions 4 of the cam members 5 and 6 are provided in the carrier 10. As is shown in FIG. 4, pins 15 which are held in their respective effective positions by pressure springs engage with their free ends these arresting recesses 17.

When the foregoing text refers to needle butts, it is intended to include butts of cams associated with the needles. Further, the present cam system is also applicable in connection with rib dials of circular knitting machines.

What is claimed is:

1. In a cam system, especially for multi-feed circular knitting machines, having a clearing cam arrangement including a tuck cam member and a clearing cam member, journaled on journal means for swinging said cam members back and forth between respective operative and inoperative positions, said cam members including cooperating means for determining the operative position of said clearing cam member by the operative position of said tuck cam member, and for determining the inoperative position of said tuck cam member by the inoperative position of said clearing cam member, said clearing cam member including means for arresting the clearing cam member in its operative position and in its inoperative position, the improvement comprising: separate arresting means positioned to cooperate with said tuck cam member to arrest the tuck cam member in its operative position independently of the clearing cam member, said journal means comprising a hollow shaft to one end of which is attached said clearing cam member, and a further shaft extending through said hollow shaft, said tuck cam. member being attached to said further shaft.

2. The cam system according to claim 1, wherein said tuck cam member 5 is shorter than said clearing cam member.

3. The cam system according to claim 1, wherein said hollow shaft and said further shaft are arranged coaxially relative to each other.

References Cited UNITED STATES PATENTS 2,043,852 6/ 1936 Holmes 6657 XR 2,260,579 10/ 1941 Miller 6657 XR 2,756,574 7/1956 Shortland 66-57 XR 3,387,466 6/1968 Beckenstein 66-57 XR 3,405,542 10/1968 Beckenstein 66-38 RONALD FELDBAUM, Primary Examiner 

